Machines for removing fins from finned tubes



June 22, 1965 R. M. s TlKELEATHER 3,190,181

MACHINES FOR REMOVING FINS FROM FINNED TUBES Original Filed Dec. 23,1958 United States Patent AO 3,190,181 MACHINES FOR REMOVING FINS FROMFINNED TUBES Robert M. Stikeleather, Holbrook, Mass., assigner toAerotin Corporation, Syracuse, N.Y. Original application Dec. 23, 1958,Ser. No. 7 82,506. Divided and this application Aug. 1, 1962, Ser. No.213,966

Y 3 Claims. -(Cl. 90-15) This invention relates to cutters for removingspirally wound tins from finned heat exchange tubes.

This application is a division of my copending application, Serial No.782,506, tiled Dec. 23, 1958, which discloses a system for cutting ofilengths of finned tubing as it emerges from a nning machine, vandpreparing the cutoif lengths of tubing for assembly in a heat exchanger.The present application is for the cutting machine which removes finsfrom the tubing to provide space for tube supports.

Spirally wound fins are caused to adhere to the tubes on which they arewound by deforming the ribbons which form the fins to cause them to curlabout and adhere to the tubes. Since in many cases the tins are notadditionally attached to the tubes as by soldering, prior to thisinvention it has not been possible to remove a predeterrice p A belt 43engages the pulleys 25 and 40. Another belt 45 engages the pulleys 26and 41.

Horizontally extending guides Stb and 51 are attached to the outer sideof the base portion 28, and are spaced apart a distance equal to theouter diameter of the tin 39.

, The guides have diverging outer portions 52 and 53 which mined numberof turns of a lin without unwinding,

bending or otherwise damaging adjacent turns of the tin.

This invention provides a pair of rotary cutters which rotate inopposite directions on opposite sides of a finned tube, one cutter beingoli-set with respect to the other cutter so that their combined widthsare equal to the space along the length of a finned tube from which thefin is to be removed. The turns of iin in that space are removed withoutany damage to the adjacent turns of the iin.

An object of this invention is to remove a predetermined number of turnsof spirally wound iin from a finned tube without damaging adjacent turnsof the 1in.

This invention will now be described with reference to the annexeddrawings, of which:

FIG. 1' is a plan view looking downwardly upon a fin cutting machineembodying this invention, a finned tube from which turns of a fin havebeen removed being shown;

FIG. 2 is an end View of the machine, the finned tube also being shown,and

FIG. 3 is a side view of the machine, showing in dashed lines, thecutters of the machine in iin cutting position on opposite sides of theiinned tube.

A trame 10 has slidably supported thereon a base 11. The trarne 1%) hasan upturned outer end 12 to which is attached an air cylinder 13. Thebase 11l has an upturned outer end 14 to which is attached piston rod 15of the cylinder 13. An electric motor 18 is mounted on the base 11, andhas a shaft 20 with a gear 19 thereon. The gear 19 is meshed with a gear21 on a shaft 22 in a journal 23 on top of the motor 18. The shaft 20has a pulley 25 attached thereto. The shaft 22 has a pulley 26 attachedthereto. The base 11 has an upturned inner end 28 on which is supportedjournal of shaft'31 of a lower cutter 32, and a journal 33 of shaft 34of an upper cutter 35, the shafts 31 and 34 being vertically aligned.Pulleys 40 and 41 are attached to the shafts 31 and 34 respec-` tively.

The cutters 32 and 35 are spaced apart a distance equal y serve tolocate a finned tube between the cutters when the latter are Vmoved toiin cutting position as will be described later.

Operation In operation, the motor 18 rotates the gears 19 and 21 inopposite directions, and the latter rotate through the pulleys 25 and26, the belts 43 and 45 respectively, and the Vpulleys 4d and 41respectively, the cutters 32 and 35 re- Y spectively, in oppositedirections. A finned tube 38 having turns of a lin at an intermediateposition to be removed, shown as removed by FIGS. 1 and 2, is supportedin front of the machine as disclosed in detail in said application.

Compressed air from a source which is not shown, is supplied into thecylinder 13, and the piston rod 15 of the latter moves the base 1l andthe cutter mechanism mounted thereon towards the tnned tube 38 until thecutters 32 and 35 are on opposite sides of the tube as shown by thedashed lines oi PEG. 3. The cutters remain in this position while theinned tube is rotated between them 360 in opposite directions asdescribed in my said application, and the rotating cutters remove thedesired nurnber of turns of the fin.

When the cutting is completed, the cylinder 13 is operated to retractits piston rod 15 and the cutter assembly, leaving the tube with a bareintermediate portion as shown by FIGS. l and 2. The motor 13 is thendeenergized until turns of a iin are to be removed from another tube.

Both cutters 32 and 35 rotate in the direction that the fin is spirallywound on the tube so as to prevent the iin from unwinding when thecutters are applied to it. Since the cutters are on opposite sides ofthe tube, this requires that they rotate in opposite directions. Y

What is claimed, is:

1. A machine for removing fin from a inned tube comprising a frame, anelectric motor supported on saidframe, a first gear and a first pulleyon the shaft of said motor, a second gear meshed with said gear, asecond shaft for said second gear, a journal supported on said frame forsaid second shaft, a second pulley on said second shaft, a firstcircular, rotary cutter, a third shaft for said cutter, a journalsupported on said frame for said third shaft, a third pulley on saidthird shaft, a second rotary, circular cutter, a fourth shaft for saidsecond cutter, a journal supported on said frame for said fourth shaft,a fourth pulley on said fourth shaft, said shafts having parallel axes,belts around said first and second and around said third and fourthpulleys, said cutters being spaced apart at their peripheral edges in adirection normal to said axes a distance equal to the diameter of a tubefrom which fin is to be removed, said cutters being displaced in thedirection of said axes so that the inner edge of one of said cutters andthe outer edge of the other one of said cutters extend substantially ina plane normal to said axes, and a pair of guides supported from saidframe between said third and fourth shafts, said guides extendingoutwardly beyond said cutters and being spaced apart in a directionnormal to said axes a distance equal substantially to the outer diameterof the fin on said tube.

2. A machine for removing fin from a finned tube comprising a frame, anelectric motor supported on said frame, a first gear and a irst pulleyon the shaft of said motor, a second gear meshed with said gear, asecond shaft for said second gear, a journal supported on said frame forsaid second shaft, a second pulley on said second shaft, a firstcircular, rotary cutter, a third shaft for said cutter, a jour- 9 r Y oi nal supported on said frame for said third shaft, a thirdV4 pulley onsaid third shaft, a second rotary, circular Cutter,

a fourth shaft for said second cutter, a journal supported on said framefor said fourth shaft,`a fourth pulley on said fourth shaft, Vsaidshafts .having parallel aries, belts-around said rst and second andaround said third andV fonrthV pulleys, said cutters being spaced apartat their peripheral edgesrin .a direction normal to saidaXes a distanceequal to the diameter of a tube from which fin is to Vbe removed, and apair of guides supported-from said frame between said third and fourthshafts, said guidesextendingoutin which'rrneans is provided foralternatelyfmoying said Wardly beyond said cutters and being spacedapart in YaV y direction 4normal to said axes a distance equalsubstantially to the outer diameter of the n on said tube.V

Y 3. The invention claimed in claim k2 inA Which;said motor, saidjournals and said guidesare supported from saidframe on a base that isslidable on said frame, and.

base forwardly from its normal position and returning said base to saidposition.

` References Cited by the l'rxraminl'l UNITED STATES 'PATENTS WILLIAM W;DYER, ng., Primary Examiner.' f Y LEON PEAR, Examiner. i

1. A MACHINE FOR REMOVING FIN FROM A FINNED TUBE COMPRISING A FRAME, ANELECTRIC MOTOR SUPPORTED ON SAID FRAME, A FIRST GEAR AND A FIRST PULLEYON THE SHAFT OF SAID MOTOR, A SECOND GEAR MESHED WITH SAID GEAR, ASECOND SHAFT FOR SAID SECOND GEAR, A JOURNAL SUPPORTED ON SAID FRAME FORSAID SECOND SHAFT, A SECOND PULLEY ON SAID SECOND SHAFT, A FIRSTCIRCULAR, ROTARY CUTTER, A THIRD SHAFT FOR SAID CUTTER, A JOURNALSUPPORTED ON SAID FRAME FOR SAID THIRD SHAFT, A THIRD PULLEY ON SAIDTHIRD SHAFT, A SECOND ROTARY, CIRCULAR CUTTER, A FOURTH SHAFT FOR SAIDSECOND CUTTER, A JOURNAL SUPPORTED ON SAID FRAME FOR SAID FOURTH SHAFT,A FOURTH PULLEY ON SAID FOURTH SHAFT, SAID SHAFTS HAVING PARALLEL AXES,BELTS AROUND SAID FIRST AND SECOND AND AROUND SAID THIRD AND FOURTHPULLEYS, SAID CUTTERS BEING SPACED APART AT THEIR PERIPHERAL EDGES IN ADIRECTION NORMAL TO SAID AXES A DISTANCE EQUAL TO THE DIAMETER OF A TUBEFROM WHICH FIN IS TO BE REMOVED SAID CUTTERS BEING DISPLACED IN THEDIRECTION OF SAID AXES SO THAT THE INNER EDGE OF ONE OF SAID CUTTERS ANDTHE OUTER EDGE OF THE OTHER ONE OF SAID CUTTERS EXTEND SUBSTANTIALLY INA PLANE NORMAL TO SAID AXES, AND A PAIR OF GUIDES SUPPORTED FROM SAIDFRAME BETWEEN SAID THIRD AND FOURTH SHAFTS, SAID GUIDES EXTENDINGOUTWARDLY BEYOND SAID CUTTERS AND BEING SPACED APART IN A DIRECTIONNORMAL TO SAID AXES A DISTANCE EQUAL SUBSTANTIALLY TO THE OUTER DIAMETEROF THE FIN ON SAID TUBE.